Wireless networks are superior to wired networks with regard to aspects such as ease of installation and flexibility. They do, however, suffer from lower bandwidth, higher delays, higher bit-error rates, and higher costs than wired networks. With the advent of Wireless Local Area Networks (WLANs), bandwidth has increased and prices have decreased on wireless networking solutions. These factors have made WLANs a very popular wireless networking solution. Given the coverage and low price, it is likely that demands for the ability to run real-time applications such as voice over IP over these networks will increase. If such applications are to become usable, considering the characteristics of wireless networks, some kind of service differentiation may be employed to let certain types of traffic get better performance.
The Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard for WLANs is the most widely used WLAN standard today. Since it may use a shared medium, it has some inherent problems, such as low medium utilization, risk of collisions and problem of providing differentiation between different types of traffic. There is a mode of operation in IEEE 802.11 that may be used to provide service differentiation, but it has been shown to perform poorly and give poor link utilization. Thus, there is an ongoing need in wireless communications for better wireless networks with improved service differentiation.
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